As functional differences have been considerably reduced among electronic devices, each manufacturer has been making efforts to increase the rigidity of electronic devices, to strengthen a design aspect of the electronic devices, and to slim the electronic devices. As one aspect of such a trend, efforts have been made to efficiently secure a space for disposing at least one antenna device that shall be essentially provided for communication among a plurality of components of the electronic devices, and at the same time, to prevent degradation of the radiating performance of antenna devices in advance and to make the antenna devices exhibit excellent performance.
Antenna devices used in an electronic device have an inverted-F antenna (IFA) or a monopole radiator as a basic structure, and a volume and number of mounted antenna radiators may be determined based on frequency, bandwidth, and a kind of each service. For example, although there is a difference in frequency from region to region in the world, typically a low band of 700 megahertz (MHz) to 900 MHz, a mid band of 1,700 MHz to 2,100 MHz, and a high band of 2,300 MHz to 2,700 MHz are used as main communication bands. In addition, wireless communication services (e.g., bluetooth (BT), global positioning system (GPS), and wireless fidelity (WIFI)) are used. While a plurality of antennas is required in order to support the aforementioned communication bands, a communication device may have a restrictive antenna volume space. In order to overcome this problem, service bands, which are similar to each other in terms of frequency bands, are lumped with each other and are designed to be split to several antennas.
For example, an antenna that is in charge of voice/data communication (e.g., general packet radio service (GPRS), wideband code division multiple access (WCDMA), or long-term evolution (LTE)), which is a major communication protocol of a terminal, may be positioned in a lower end of an electronic device where few metallic components to inhibit antenna performance exist. By European standards, 24 bands in total may be implemented including 2G (global system for mobile communication (GSM)850, evolved GSM (EGSM), digital communication system (DCS), personal communication system (PCS)), WCDMA (B1, B2, B5, B8), and LTE (B1, B2, B3, B4, B5, B7, B8, B12, B17, B18, B19, B20, B26, B38, B39, B40, B41). In fact, it is difficult to meet service providers' specifications and specific absorption rate (SAR) standards and to minimize effects on the human body while implementing all the bands in one antenna. Thus, service bands, of which the frequency bands are similar to each other over at least two regions, may be lumped with each other so as to implement an antenna. As an example, 2G (GSM850, EGSM, DCS, PCS), WCDMA (B1, B2, B5, B8) and LTE (B1, B2, B3, B4, B5, B8, B12, B17, B18, B19, B20, B26, B39) may be implemented in one antenna, and an antenna for LTE (B7, B38, B40, B41) may be designed in another antenna.
In addition, in the case where the exterior of an electronic device is constituted with a metal member (e.g., a metal bezel) according to the recent trend, an antenna that is designed using the metal member is used as an antenna radiator rather than separately designing the antenna, unlike an injection molded product of a dielectric material.
For example, in the case where a metal bezel used in the rim of an electronic device is utilized as an antenna radiator, a specific area of the metal bezel may be severed by split portions made of a dielectric material and an electric distance of the antenna from a power feeding unit such that the antenna radiator can be implemented to operate in a desired frequency band.
Recently, in many cases, at least two metal members, which are severed by split portions, are electrically connected and used. In such cases, power feeding is performed in one metal member at one side with reference to a split portion, and the remaining one radiator may be applied as a parasitic radiator in order to expand the bandwidth of the antenna device or to change the operating frequency band of the antenna device. According to one embodiment, in such a case, two metal members, which are split by a split portion, are electrically connected and used.
However, in such a case, one metal member, which is fed with power, may also be used not only as an antenna radiator, but also as a sensing member by a sensor module, and it may be necessary for the two metal members to have a split structure in order to optimize a leakage current generated in neighboring metal members. In addition, it may also be necessary for the two metal members to have a mutual electric connection structure in order to optimize the radiation performance of the antenna radiator. At present, two electrically connected metal members may contribute to the improvement of the antenna performance of an antenna device, but may cause a performance degradation of the electronic device.